1. Field of the Invention
The present invention relates to a system and method of pointed position detection, a presentation system, and also a program.
2. Description of Related Art
There are systems that enable presentations in which a pointer implement is used to project a light spot onto a screen.
With such a system, erroneous recognition can occur during the extraction of the light spot from an image signal of an image pick-up means when infrared light is used as the light spot, due to the surrounding environment, more specifically, due to external light such as an infrared remote controller signal used for controlling the projector or sunlight intruding from the exterior.
The present invention was devised in the light of the above described technical problem and has as an objective thereof the provision of a system and method of pointed position detection, a presentation system, and also a program that make it possible to detect a position accurately without any recognition errors, when it comes to detecting the position of a light spot that has been projected onto a screen or the like, from an image signal of an image pick-up means.
(1) In order to solve the above described technical problem, there is provided a pointed position detection system in accordance with the present invention which detects a position of a light spot that is projected into an image display region by using a pointer implement, the pointed position detection system comprising:
image pick-up means which picks up an image of the image display region;
position detection means which detects a pointed position of the light spot within the picked-up image display region; and
receiver means which receives a state signal transmitted in from the pointer implement during a pointing operation performed by the pointer implement;
wherein the position detection means detects a position of the light spot as a pointed position in the image display region, based on reception timing of the state signal.
(2) According to the present invention, there is provided a pointed position detection system which detects a position of a light spot that is projected into an image display region by using a pointer implement, the pointed position detection system comprising:
image pick-up section which picks up an image of the image display region;
position detection section which detects a pointed position of the light spot within the picked-up image display region; and
receiver section which receives a state signal transmitted in from the pointer implement during a pointing operation performed by the pointer implement;
wherein the position detection section detects a position of the light spot as a pointed position in the image display region, based on reception timing of the state signal.
(3) According to the present invention, there is provided a program embodied on an information storage medium or in a carrier wave for detecting a position of a light spot that is projected into an image display region by using a pointer implement, the program implementing in a computer:
position detection means which detects a pointed position of the light spot within the image display region, based on an image signal from an image pick-up means which picks up an image of the image display region; and
means for causing a receiver means to receive a state signal that is transmitted in from the pointer implement during a pointing operation performed by the pointer implement;
wherein the position detection means detects a position of the light spot as a pointed position in the image display region, based on reception timing of the state signal.
(4) According to the present invention, there is provided a pointed position detection method of detecting a position of a light spot that is projected into an image display region by using a pointer implement, the method comprising:
an image picking-up step of picking up an image of the image display region;
a position detection step of detecting a pointed position of the light spot within the picked-up image display region; and
a reception step of receiving a state signal transmitted in from the pointer implement during a pointing operation performed by the pointer implement;
wherein the position detection step detects a position of the light spot as a pointed position in the image display region, based on reception timing of the state signal.
In addition to enabling detection of the position of the light spot by image processing based on the imaging result, the present invention makes it possible to detect the pointed position from consideration of timing that is indicated by the pointer implement in practice by using the state signal, thus enabling a reduction in erroneous recognition due to external light such as sunlight or from a remote controller that also uses infrared light, which enables an increase in the reliability of pointed position detection.
(5) In each of the pointed position detection system and program, the position detection means may perform correction calculations in the detection of the pointed position, based on pointed position data for a plurality of frames.
(6) The position detection step may perform correction calculations in the detection of the pointed position, based on pointed position data for a plurality of frames.
The precision of position detection is generally determined by the frame rate and it is difficult to detect the pointed position at an interval that is shorter than a sampling interval of the image pick-up means. The employment of a configuration that performs correction calculations ensures a higher detection precision, because the correction calculations ensure that the detection of the true pointed position is based on sampling points before and after the time of the actual pointing operation, even when the pointing is done at a timing that does not match the sampling timing.
Note that various methods could be applied to these correction calculations, such as linear interpolation or curve interpolation.
(7) In each of the pointed position detection system and program, the position detection means may perform correction calculations in the detection of the pointed position that are based on delay time data which indicates a delay time comprising at least one of a processing delay time and a transfer delay time up until the detection of the state signal.
(8) The position detection step may perform correction calculations in the detection of the pointed position that are based on delay time data which indicates a delay time comprising at least one of a processing delay time and a transfer delay time up until the detection of the state signal.
This aspect of the invention ensures accurate position detection, by correction calculations that take into consideration any delay between the time at which the operating section is actually operated and the time at which the state signal is received.
(9) In each of the pointed position detection system, pointed position detection method, and program, the pointer implement may comprise:
light spot projection means which projects the light spot when a predetermined operating section is operated; and
transmitter means which transmits the state signal in synchronization with the projection of the light spot.
Since this aspect of the invention makes it possible to use a common operating section, such as a switch, to project the light spot and also send a state signal at substantially the same time, it enables the operator to use the system with a minimum of effort, in comparison with a device that is provided with an operating section for the light spot and a separate operating section for the state signal.
(10) In this pointed position detection system, the state signal may comprise an identification signal for the pointer implement; and
the pointed position detection system may further comprise identification means which identifies the pointer implement, based on the identification signal for the pointer implement.
(11) In the program of the invention, the state signal may comprise an identification signal for the pointer implement; and
the program may further implement in a computer, identification means which identifies the pointer implement, based on the identification signal for the pointer implement.
This aspect of the invention enables a wide range of different types of presentation because it makes it possible to identify each pointer implement, even if one person is using a plurality of pointer implements or two or more people are using a plurality of pointer implements.
(12) In each of the pointed position detection system and program, the transmitter means may transmit the state signal in a wireless fashion; and
the receiver means may receive the state signal in a wireless fashion.
This aspect of the invention makes it easier for the operator to use the system because the use of wireless means to transfer the state signal removes the need for any cables or the like for transferring signals.
(13) The program may further implement in a computer:
means for causing an image display means to display an image in the image display region; and
processing means which performs processing in which a pointed position detected by the position detection means is reflected in predetermined data processing.
This aspect of the invention makes it possible to perform various types of processing.
(14) According to the present invention, there is provided a presentation system for performing a presentation in which a light spot is projected by a pointer implement into an image display region, the presentation system comprising:
display means which displays an image in the image display region;
the above-described pointed position detection system; and
processing means which performs processing in which a pointed position detected by the position detection means is reflected in predetermined data processing.
In addition to enabling detection of the position of the light spot by image processing based on the imaging result, the present invention makes it possible to detect the pointed position from consideration of timing that is indicated by the pointer implement in practice by using the state signal, thus enabling a reduction in erroneous recognition due to external light such as sunlight or from a remote controller that also uses infrared light, which enables an increase in the reliability of pointed position detection. This enables the presenter to give the presentation while indicating the images in comfort, with no erroneous recognition of the pointed position.
Note that the data processing could also be applied to calculation of the cursor display position, changes in the display of the cursor, icon pointing determination processing, or icon display modification, by way of example.
(15) In each of the presentation system and program, the processing means may perform position control of a cursor comprised within the display image, based on the detected pointed position.
(16) The pointed position detection method may further comprises a step of performing position control of a cursor comprised within the display image, based on the detected pointed position.
This aspect of the invention enables control over the position at which a cursor is displayed, relating to the pointed position. This makes it possible for the cursor to follow the pointed position accurately during the presentation, with no erroneous recognition due to external light, thus enabling more effective presentations.